Welding Tips and Tricks

Hello I am newer to welding about all I have done is fixed broken tools around the farm. I am now tackling my first time welding on a bike. The weld is a bracket for my sidecar because the frame clamp is slipping so what I plan on doing is welding a threaded tube on a pice of angle iron but I'm not sure how to get a good weld on the rounded surface to a flat surface.

What's the diameter and wall thickness of the tube, and the thickness of the flat stock?

If you have access to the back side of the flat stock, I'd drill a hole the size of your round tube, stick the tube most of the way through the flat stock, weld the outside, then weld the back side too. Or only weld the back side if you don't want to see the welds.

I've done this alot when I need a threaded bolt sticking out of a flat piece, but I don't want to actually have it a free floating bolt. I'll cut off the head of the bolt, and weld it on the back side of the flat stock like a plug/rosette weld.

If you could provide us with some more info we will be able to better help you. Things like material thickness, composition if you know it, sketch of the joint or real pictures, tools you have available to do the job (torches, grinders, welding machines and material) can all be helpful in determining the best way to approach the work.

Thanks,
Jesse

Sorry, but I am of the thought that if you are asking this question you probably shouldn't weld it. Your passenger would probably appreciate it

Sorry I have been occupied with work I make a sketch of what I want . I have a mig a bench grinder angle grinder. I haven't picked up my materials yet I'm just in the planing stage but Honda and BMW used mild steel in there motorcycle frames with no problem for years I'm thinking quarter inch steel

The angle will be bolted to a spot in the frame where 2 parts of the frame bolt together and the tube will be threaded.
As for the comment about how I shouldn't do this if I have to ask all I have to say is if no one ever asks no one will ever learn anything.

I think what the other poster was getting at is that this would be considered a critical weld and with you and your passengers safety in mind, you might want to get a more experienced welder to do it for you. You might even find it hard to get someone to do a weld like that....huge liability. Please don't take offense but safety is a prime concern.

@mantree,
To your question of getting a good weld on the part, the joint you have pictured is actually in all regards no different than a basic fillet weld. Getting weld down into the recess where the pipe meets the angle is going to be near impossible but it's not all that critical either. We don't know from one question your ability, but if you can lay a proper weld bead, you can make this weld.

If your weld is tied in well to the angle as well as the threaded tubing, it doesn't matter that it's not where the two surfaces meet. It's really no different that putting a small gusset in there and welding it to the angle and the other end to the tubing. I'm not firmiliar with how a sidecar attaches to a motorcycle, but if this is just something in addition to what's in place and already holding it, then I would say the safety concerns should go down but now away.

I hope this makes sense.

Len

This is replacing a frame clamp that has been just bugging me because it keeps getting loose there are 3 other mounts but this one just bugs me by always being loose.

mantree,
I thought a little about your fixture and think it would be way stronger if you ran flat strap as gussets and attached them higher on the threaded tube.

Len


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So weld the tube on with a good strong bead and then gusset it. That sounds like a fantastic idea. I will do some measuring and may have to trim a radiator support to fit it. If this was a air cooled I would just have a cross bar on the down tubes but the rad makes it a bit more difficult

So I went and took a look all I will have to do is trim a pice of the fairing

You can only see one of the 2 frame bolts here the other one is under the plastic

This is the clamp being replaced the bolts in the sides were installed after the first time it came off and it has been bothering me ever since

My concern came from...

mantree wrote:Hello I am newer to welding about all I have done is fixed broken tools around the farm. I am now tackling my first time welding on a bike. The weld is a bracket for my sidecar because the frame... ... I'm not sure how...

So to me New+only fixed broken farm tool+sidecar+frame+not sure how=generally not good out come. The modified version for someone in this instance makes way more sense

You're talking about a challenging weld. Getting penetration to the bottom of the joint is impossible. Shrinkage as the weld cools will pull it out of shape. When finished, if your weld is sound, the flat stock will no longer be flat, the tube stock will no longer be round. I'd use DOM tubing thick enough to be adequate after it is deformed, then after welding, drill it and tap it cold. I would lay a couple pieces of round stock between, and weld them into the joint.

So this morning I had a bit of a break threw on a less challenging method there for less likely to screw it up. My thought was to drill threw a pice of flat stock and weld the tube threw instead of welding on the side of the angle

Then gusset along the tube in 2 or 3 places. Any thoughts on this plan?

mantree,
In your second design there is kind of a built in failsafe in that if the weld fails the threaded tube would still be captured by the bracket and only would be able to move inside the hole. I think this might be a better option if you're not sure of your welding abilities.

If I were you I would build the bracket and put it in place and then post some pictures here and get some opinions on if it will work. It hard to get a good sense of where this bracket will go and what forces will be put on it from what we've seen so far. You can just tack up a mock version and take whatever input into final version makes sense. There's some sharp people here that can offer you good advice if they can get the full picture.

Len

I have the weekend off next week so I will try to get in to the shop since it is to cold to be doing wiring on the bike